Arcteq AQ-E215, Instruction Manual

Page: 72 / 207

IL3RMS Fundamental RMS measurement of phase L3 (C) current 5 ms
U
1
RMS Fundamental RMS measurement of voltage U
1
/V
5 ms
U
2
RMS Fundamental RMS measurement of voltage U
2
/V
5 ms
U
3
RMS Fundamental RMS measurement of voltage U
3
/V
5 ms
U
4
RMS Fundamental RMS measurement of voltage U
4
/V
5 ms
Pick-up
The I
set
setting parameter controls the pick-up of the I> function. This de nes the maximum allowed
measured current before action from the function. The function constantly calculates the ratio
between the
I
set
and the measured magnitude (
I
m
) for each of the three phases. The reset ratio of 97
% is built into the function and is always relative to the I
set
value. The setting value is common for all
measured phases, and when the
I
m
exceeds the
I
set
value (in single, dual or all phases) it triggers the
pick-up operation of the function.
The fault has to be in the monitored direction and it must ful ll the terms in order for the alarm to
trigger. The fault direction can be set to forward or reverse. The fault detection area is ±88
degrees (176°), and the reference angle is based on the angle of the calculated positive sequence
voltage
U
1
. If the
U
1
voltage is not available and only line-to-line voltages are measured, the reference
angle is based on a healthy line-to-line voltage. During a short-circuit the reference angle is based on
impedance calculation. If the voltage drops below 1 V in the secondary side, the angle memory is used
for 0.5 seconds. The angle memory forces the reference angle to be equal to the value measured or
calculated before the fault. The angle memory captures the measured voltage angle 100 ms before the
fault starts. After 0.5 seconds the angle memory is no longer used and the reference angle is forced to
0°. The inbuilt reset ratio for the fault detection angle is 2°.
Table. 5.3.3. - 53. Pick-up settings.
Name Range Step Default Description
Characteristic direction
0: Forward
1: Reverse
2: Non-directional
- 0: Forward Selects the direction of the characteristic.
Operating sector size (±) 1.0…170.0 deg 0.1 deg 88 deg The size of the pick-up area.
Operating sector center (±) -180.0…180.0 deg 0.1 deg 0 deg The center of the pick-up area.
Pick-up> (I
set
) 0.10…40.00 × I
n
0.01 × I
n
1.20 × I
n
The pick-up setting.
The pick-up activation of the function is not directly equal to the START signal generation of the
function. The START signal is allowed if the blocking condition is not active.
AQ-E215
Instruction manual
Version: 2.01
71 © Arcteq Relays Ltd